摘要：The genus Achillea L. (Asteraceae) is widely distributed in Turkey and used as folk remedies for their several biological effects. In this study hydro-distilled essential oils of Achillea biebersteinii and Achillea teretifolia were analysed by gas chromatography and gas chromatography-mass spectrometry (GC-MS) techniques, simultaneously. Piperitone (44.7%), 1,8-cineole (15.9%) and camphor (4.9%) were the main constituents of A. biber^teinii oil, while 1,8-cineole (18.8%), camphor (17.6%), p-cy-mene (13.7%) and chrysanthenone (10.2%) were the main constituents of A. teretifolia essential oil. The oils of A. biebersteinii and A. teretifolia were subjected to a screening for their antimicrobial activities by using broth microdilution technique. A. bib-ersteinii volatile oil showed an inhibitory effect at the concentrations ranging from 31.25 to >2000 ^g/mL while A. teretifolia oil was effective at 250 to >2000 ^g/mL. A. biber^teinii volatile oil remarkably inhibited the growing of Candida utilis and C. krusei pathogenic yeast at the doses of 31.25 and 125 ^g/mL respectively.
